Sensitive determination of methadone in human serum and urine by dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet followed by HPLC-UV

Effects of Ge, Si, and B doping on the adsorption and detection properties of C60 fullerene towards methadone in gas and aqua phases: a DFT study

CONTEXT

Methadone can be abused and caused addictive and has various side effects. Therefore, the development of a fast and reliable diagnosis technique for its monitoring is essential. In this work, applications of C₆₀, GeC₅₉, SiC₅₉, and BC₅₉ fullerenes were investigated utilizing density functional theory (DFT) to find a suitable probe for methadone detection. The C₆₀ fullerene indicated weak adsorption energy for methadone sensing. Therefore, for the construction of the fullerene with good property for methadone adsorption and sensing, the GeC₅₉, SiC₅₉, and BC₅₉ fullerenes have been studied. The adsorption energy of GeC₅₉, SiC₅₉, and BC₅₉ in the most stable complexes were calculated at -2.08, -1.26, and -0.71 eV, respectively. Although GeC₅₉, SiC₅₉, and BC₅₉ all showed strong adsorption, only BC₅₉ present a high sensitivity for detection. Further, the BC₅₉ fullerene showing a proper short recovery time (about 1.11 × 10^-6 s for methadone desorption). Water as a solution is used to simulate the behavior of fullerenes in the body fluids, and results indicated that the selected pure and complex nanostructures are stable in water. The UV-vis spectrums indicated that the after adsorption of methadone on the BC₅₉ exhibits shift toward the lower wavelengths (blue shift). Therefore, our investigation indicated that the BC₅₉ fullerene is an excellent candidate for methadone detection.

METHODS

The interaction of methadone with pristine and doped C60 fullerenes surfaces was calculated using the density functional theory calculations. The GAMESS program and M06-2X method with a 6-31G(d) basis set were used for computations. Since the M06-2X method overestimates the LUMO-HOMO energy gaps (Eg) of carbon nanostructures, the HOMO and LUMO energies and Eg were investigated at the B3LYP/6-31G(d) level of theory using the optimization calculations. UV-vis spectra of excited species were obtained through the time-dependent density functional theory. To simulate the human biological fluid, the solvent phase was also evaluated in adsorption studies, and water was considered a liquid solvent.

Development of a β-cyclodextrin-modified gold nanoparticle-assisted electromembrane extraction method followed by capillary electrophoresis for methadone determination in plasma

In this study, gold nanoparticles (AuNPs) modified with β-cyclodextrin (β-CD) were used to assist with electromembrane extraction (EME) and were coupled with capillary electrophoresis (CE) and ultraviolet (UV) detection (CE-UV) for the extraction and measurement of methadone from plasma samples. A β-CD-modified AuNP-reinforced hollow fiber (HF) was utilized in this work. The β-CD-modified AuNPs act as an absorbent and provide an extra pathway for the analyte extraction. For obtaining the effect of the presence of β-CD-modified AuNPs in the HF pores, the extraction efficiency of the EME and β-CD-modified AuNPs/EME techniques were compared. Different parameters influencing the extraction efficacy of the EME and β-CD-modified AuNPs/EME methods were optimized. Optimal extractions were performed with 1-octanol as the organic solvent in the supported liquid membrane (SLM), with an applied voltage of 10 V as the driving force across the SLM, and with pH 7.0 in the donor solutions with a stirring speed of 1000 rpm after 20 min and 25 min for the β-CD-modified AuNPs/EME and EME methods, respectively. Under optimal conditions, compared with the EME method, the β-CD-modified AuNPs/EME method exhibited increased extraction efficacy in a short time. The β-CD-modified AuNPs/EME technique demonstrated a lower limit of detection (5.0 ng mL^-1), higher extraction recovery (68%), and a more optimal preconcentration factor (135). Furthermore, this method was successfully utilized for measuring methadone in real plasma samples.

Response surface optimization of a vortex-assisted dispersive liquid-liquid microextraction method for highly sensitive determination of repaglinide in environmental water by HPLC/UV

A vortex-assisted dispersive liquid–liquid microextraction (DLLME) method, mated to chemometrics and combined with HPLC/UV detection was optimized and validated for enrichment and determination of repaglinide in environmental samples using nateglinide as an internal standard (IS). A phosphate buffer (10 mM, pH 2.5): acetonitrile (45:55, v/v) was used as a mobile phase with a flow rate of 1 mL/min in an isocratic elution mode. Chemometrics-assisted optimization was performed using a quadratic integrated d-optimal design. The developed model assessed the statistical significance of the independent variables and their interactions to attain the optimum conditions revealing that extractant type, extractant volume and pH are the most influential factors. Optimization of the extraction procedures was performed with the aid of Design Expert 8® software, which suggested 58 different experiments. The optimal conditions were 30 µL of 1-octanol as extractant, 100 µL of acetonitrile as a disperser at pH 8. Under the optimized conditions, the method showed linearity over the range of 1–100 ng/mL with a limit of detection of 0.4 ng/mL. The accuracy, the intra- and inter-day precision were assessed, the %recoveries were found to be between 98.48 and 100.81% with %RSD lower than 1.3. Using chemometrics in method optimization helped achieve the maximum possible enrichment with the least effort, time, and reagents while considering all possible interactions between variables.

Progress in pretreatment of methadone: an update since 2015

Methadone, a µ-opioid receptor agonist, is widely used in pain-relieving and treating opioid dependence. If not strictly controlled, as an opioid substitute, it can lead to abuse and cause more severe withdrawal responses than heroin. Also, overdose or abuse of this drug in clinical use may provide severe side effects such as apnea, circulatory collapse, cardiac arrest, and even death. For these reasons, simple, rapid, and efficient methods have been developed for the pretreatment of methadone. This review presents a comprehensive conclusion of the pretreatment methods used for methadone in various sample matrices, focusing on the developments since 2015. Traditionally used pretreatment methods like solid-phase extraction and liquid-liquid extraction are discussed and newly developed methods like solid-phase microextraction and liquid-liquid microextraction along with new materials applied are focused.

Sensitive determination of vincristine in plasma of children with leukaemia using vortex-assisted dispersive liquid-liquid microextraction based on hydrophobic deep eutectic solvent

Vincristine has a wide spectrum of clinical activity and is currently used in the treatment of leukemia. Despite its high therapeutic properties, vincristine has common side effects. Accordingly, it is desirable to determine vincristine in plasma for the use of the drug with strict monitoring. In the present research, for the first time a hydrophobic deep eutectic solvent (DES) composed of methyltrioctylammonium chloride (MTOAC) and n-butanol in a molar ratio of 1 : 3 was used as the extractant in dispersive liquid-liquid microextraction (DLLME) for the extraction and determination of vincristine in the plasma of children with leukemia prior to its analysis by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). Under optimal experimental conditions, the method showed good linearity with a correlation coefficient (R 2) of 0.9986 in the linear range of 0.06-300 μg L-1, low limit of detection of 0.02 μg L-1 and acceptable extraction efficiency (EE) of 88.4%. In the final stage of the study, this proposed technique was successfully applied to determine vincristine in real plasma, and the obtained results demonstrated the ability of the synthesized DES to extract drugs from biological fluids.

Novel deep eutectic solvent-based liquid phase microextraction for the extraction of estrogenic compounds from environmental samples

Steroid hormones, such as estrone (E1), 17β-estradiol (E2), 17β-ethinylestradiol (EE2) and estriol (E3) are a group of lipophilic active substances, synthesized biologically from cholesterol or chemically. A pH-switchable hydrophobic deep eutectic solvent-based liquid phase microextraction (DES-LPME) technique was established and combined with gas chromatography-mass spectroscopy for the determination of estrogenic compounds in environmental water and wastewater samples. A DES was synthesized using l-menthol as HBA and (1S)-(+)-camphor-10-sulfonic acid (CSA) as HBD, and used as a green extraction solvent. By adjusting the pH of the solution, the unique behavior of the DES in the phase transition and extraction of the desired analytes was investigated. The homogenization process of the mixture is done only by manual shaking in less than 30 seconds and the phase separation is done only by changing the pH and without centrifugation. Some effective parameters on the extraction and derivatization, such as molar ratio of DES components, DES volume, KOH concentration, HCl volume, salt addition, extraction and derivatization time and derivatization prior or after extraction were studied and optimized. Under the optimum conditions, relative standard deviation (RSD) values for intra-day and inter-day of the method based on 7 replicate measurements of 20 ng L⁻¹ of estrogenic compounds and 10 ng L⁻¹ for internal standard in different samples were in the range of 2.2–4.6% and 3.9–5.7%, respectively. The calibration graphs were linear in the range of 0.5–100 ng L⁻¹ and the limits of detection (LODs) were in the range of 0.2–1.0 ng L⁻¹. The relative recoveries of environmental water and wastewater samples which have been spiked with different levels of target compounds were 91.0–108.8%.

A pH-switchable hydrophobic deep eutectic solvent-based liquid phase microextraction (DES-LPME) technique was established and combined with gas chromatography–mass spectroscopy for the determination of estrogenic compounds in environmental samples.

Extraction and determination of strobilurin fungicides residues in apple samples using ultrasound-assisted dispersive liquid-liquid microextraction based on a novel hydrophobic deep eutectic solvent followed by H.P.L.C-U.V

In this study, several novel and natural hydrophobic deep eutectic solvents (D.E.Ss) were prepared using methyl trioctylammonium chloride (M.T.O.A.C) as H.B.A and different types of straight chain alcohols as H.B.Ds. One of the D.E.Ss composed of M.T.O.A.C and n-butanol was advantageously used to develop an ultrasound-assisted dispersive liquid-liquid microextraction (U.A-D.L.L.M.E) method combined with high-performance liquid chromatography-ultraviolet detection (H.P.L.C-U.V) for the determination of some strobilurin fungicides in apple samples. Several important parameters influencing extraction efficiency were investigated and optimised, including the type and volume of extractant in ultrasound stage, sonication time, the type and volume of D.E.S, sample solution pH and effect of salt addition. Under optimal experimental conditions, the method showed good linearity with correlation coefficients (R²) of 0.9985 - 0.9991 in the linear range of 4-1500 μg kg^-1, low limits of detection of 1.5-2 μg kg^-1 and acceptable extraction recoveries in the range of 76-92%. Enrichment factor was in the range of 95-115. The proposed method was successfully applied for the extraction and preconcentration of trace fungicides in apple samples, and the results demonstrated the potential of the synthesised D.E.S for the extraction and determination of contaminants in aqueous samples.

Novel hydrophobic deep eutectic solvent for vortex-assisted liquid phase microextraction of common acaricides in fruit juice followed by HPLC-UV determination

In the present research, several novel and natural hydrophobic deep eutectic solvents (DESs) were prepared using methyltrioctylammonium chloride (MTOAC) as the hydrogen bond acceptor (HBA) and different types of straight chain alcohols as hydrogen bond donors (HBDs). One of the DESs composed of MTOAC and n-butanol was advantageously used to develop a vortex-assisted liquid phase microextraction (VALPME) method combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) for the determination of common acaricides in fruit juice samples. Several important parameters influencing extraction efficiency were investigated and optimized, including the type and volume of DES, sample solution pH, effect of salt addition and, extraction and vortex time. Under optimal experimental conditions, the method showed good linearity with the correlation coefficients (R 2) of 0.9986-0.9991 in the linear range of 2-300 μg L-1, low limits of detection of 0.5-1 μg L-1 and acceptable extraction recoveries in the range of 85-93%. The proposed method was successfully applied for the extraction and preconcentration of trace acaricides in real fruit juice samples, and the results demonstrated the potential of the synthesized DESs for the extraction and determination of contaminants in aqueous samples.

Review of LC techniques for determination of methadone and its metabolite in the biological samples

Methadone (MTD) is a synthetic analgesic drug used for treating opioid dependence and effectively used clinically for patients with severe pain. The abuse of MTD may lead to poisoning, disorder in the central nervous system and even death. The regular monitoring of MTD in biological matrices including serum, plasma and urine samples is an effective way to control abuse of MTD. In this manner, the selection of analytical monitoring of MTD in biological matrices is of paramount importance. This study was conducted to review high-performance liquid chromatography (HPLC) techniques carried out on MTD and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in the biological samples during 2015-June 2021.

Solidified floating organic droplet microextraction coupled with HPLC for rapid determination of trans, trans muconic acid in benzene biomonitoring

Benzene is one of the carcinogenic compounds in the work environments. Exposure assessment of benzene through biological monitoring is an acceptable way to accurately measure the real exposure in order to conducting the health risk assessment, but it is always complicated, laborious, time consuming and costly process. A new sensitive, simple, fast and environmental friendly method was developed for the determination of urinary metabolite of benzene, trans trans muconic acid (t,t-MA) by dispersive liquid-liquid micro extraction based on solidification of floating organic droplet coupled with high-performance liquid chromatography with ultra violet detector. Central composite design methodology was utilized to evaluate the effective factors on the extraction output of the target metabolite. The calibration curve was plotted in the concentration ranges of 0.02-5 µg mL^-1. The precision and accuracy of the method were assayed via the relative standard deviation (RSD%) and relative recovery (RR%) using spiked samples with three replications. The RR% and RSD% of the optimized method were 86.9-91.3% and 4.3-6.3% respectively. The limit of detection (LOD) of the method was 0.006 µg mL^-1. The level of t,t-MA in real samples was ranged from 0.54 to 1.64 mg/g creatinine. We demonstrated that t,t-MA can be extracted and determined by an inexpensive, simple and fast method.

Application of Microextraction-Based Techniques for Screening-Controlled Drugs in Forensic Context-A Review

The analysis of controlled drugs in forensic matrices, i.e., urine, blood, plasma, saliva, and hair, is one of the current hot topics in the clinical and toxicological context. The use of microextraction-based approaches has gained considerable notoriety, mainly due to the great simplicity, cost-benefit, and environmental sustainability. For this reason, the application of these innovative techniques has become more relevant than ever in programs for monitoring priority substances such as the main illicit drugs, e.g., opioids, stimulants, cannabinoids, hallucinogens, dissociative drugs, and related compounds. The present contribution aims to make a comprehensive review on the state-of-the art advantages and future trends on the application of microextraction-based techniques for screening-controlled drugs in the forensic context.

Determination of common organophosphorus pesticides in the blood of children with acute leukaemia using a double-solvent system as a novel extractant for dispersive liquid-liquid microextraction

In this research, a new mode of dispersive liquid-liquid microextraction based on a double-solvent system (DLLME-DSS) was developed for the extraction and preconcentration of organophosphorus pesticides (OPPs) in the blood of children with acute leukaemia prior to determination by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In the present method, two long normal chain alcohols are mixed in a particular ratio, and then injected into the sample solution, which is magnetically stirred. In this case, the mixture of the two alcohols changes to a new aggregate extractant. This new double-solvent is used as an extractant, which has a higher extraction power than any of its components alone. Under the optimum conditions, the calibration graph was linear in the rage of 3-600 μg L-1 with detection limits of 1 to 2 μg L-1. Relative standard deviations (RSDs) including intra-day and inter-day of the method based on 7 replicate determinations of 100.0 μg L-1 for each analyte were in the range of 2.9-4.7% and 3.8-6.1%, respectively. The results proved that DLLME-DSS is a sensitive, very simple, inexpensive, environmentally friendly, rapid and efficient method for the preconcentration of trace amounts of OPPs in blood samples.

Assessment of carcinogenic and toxic substances in 'Insunko' herb

There has emerged a herb in Zambia called 'insunko' which has unknown chemical composition. The use of 'insunko' herb with unknown chemical composition has brought mixed feelings among many Zambians. This study, therefore, aimed to assess the toxic and carcinogenic substances in'insunko' herb. 'Insunko' herb was purchased from Chipata, Lusaka, Mpika, Mwense, Kitwe, and Solwezi. 5 samples were collected from each of these districts and were thoroughly mixed to give 6 consolidated samples (n = 6). Nicotine and, nitrosamines were analysed using UV spectrometer lambda 35 Perkin Elmer while trace metals were analysed using ICP-MS Inductively Coupled Plasma Mass Spectroscopy (Agilent Technologies, Santa Clara, CA, USA). Nicotine, nitrosamines, and trace metals were detected in high concentrations. The concentrations ranged from 3.87 to 9.83 mg/kg for nitrosamines and 10.94-34.01 mg/kg for nicotine. Hazard Indexes for arsenic, cadmium, chromium, manganese, and copper were greater than one (HI > 1). 'Insunko' herb is a potentially toxic and carcinogenic substance because it contains toxic and carcinogenic constituents in high concentrations. These toxic and carcinogenic constituents have been confirmed to cause gastrointestinal disorders, cancers, degenerative, cardiovascular, hematopoietic, neurologic and cognitive problems as well as male infertility.

Solid-phase extraction followed by deep eutectic solvent based dispersive liquid–liquid microextraction and GC-MS detection of the estrogenic compounds in wastewater samples

SPE combined with deep eutectic solvent based dispersive liquid–liquid microextraction has been developed as a sensitive technique for the ultra preconcentration of estrogenic compounds in wastewater samples prior to their analysis by GC-MS.

Homogeneous liquid–liquid microextraction based on liquid nitrogen-induced phase separation followed by GFAAS for sensitive extraction and determination of lead in lead-adulterated opium and refined opium

Herein, we developed a novel homogeneous liquid–liquid microextraction based on liquid nitrogen-induced phase separation (HLLME-LNPS) for the extraction and determination of lead (Pb) in Pb-adulterated opium and refined opium by GFAAS analysis. In this procedure, first, 400 μl of acetonitrile (extractant) containing 7.0 μl of diethyl dithiophosphoric acid (DDTP) is injected into a sample solution and a homogeneous solution is formed. Subsequently, the homogeneous mixture is cooled using liquid nitrogen for 16 seconds. By this process, due to the difference in the freezing points of the organic and aqueous phases, the homogeneous state is broken and the Pb-DDTP species are extracted into the liquid organic phase collected on top of the frozen aqueous phase. The introduced method exhibited a good linearity with a coefficient of determination (r²) of 0.9988 and an acceptable linear range of 0.6–100 μg l⁻¹. Accordingly, the detection limit was 0.2 μg l⁻¹ (S/N = 3) for Pb ions, and a high enrichment factor was obtained. The proposed method was successfully utilized to determine trace levels of Pb in opium samples. The results of the sample analysis showed that 65% of the opium samples and 85% of the refined opium samples had much higher than expected levels of contaminating Pb, and this contamination poses a serious threat to drug users.

Herein, we developed a novel homogeneous liquid–liquid microextraction based on liquid nitrogen-induced phase separation (HLLME-LNPS) for the extraction and determination of lead (Pb) in Pb-adulterated opium and refined opium by GFAAS analysis.

Rapid liquid-phase microextraction of analytes from complex samples on superwetting porous silicon for onsite SALDI-MS analysis

To simplify the pretreatment process of complex samples is a key step for rapid detection. Herein, we report a single-step method to rapidly extract analytes with liquid-phase microextraction (LPME) from complex samples on a superwetting porous silicon (PSi) for onsite detection with surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The operation time is less than 3 min with this simple method. The limit of detection (LOD) of malachite green in lake water is lowered to 10^-13 M, that of verapamil and methadone in whole blood is down to 10^-11 M and 10^-13 M, in urine is 10^-13 M and 10^-14 M, respectively; and the ranges of quantification is up to 8 or 9 orders of magnitude with high precision (coefficients of determination (R²) > 0.98) for the complex samples. This method could provide an approach to directly extract target compounds from complex samples on substrate for SALDI-MS analysis.

Solid-phase microextraction of methadone in urine samples by electrochemically co-deposited sol-gel/Cu nanocomposite fiber

Electrochemically co-deposited sol-gel/Cu nanocomposites have been introduced as a novel, simple and single-step technique for preparation of solid-phase microextraction (SPME) coating to extract methadone (MDN) (a synthetic opioid) in urine samples. The porous surface structure of the sol-gel/Cu nanocomposite coating was revealed by scanning electron microscopy. Direct immersion SPME followed by HPLC-UV determination was employed. The factors influencing the SPME procedure, such as the salt content, desorption solvent type, pH and equilibration time, were optimized. The best conditions were obtained with no salt content, acetonitrile as desorption solvent type, pH 9 and 10 min equilibration time. The calibration graphs for urine samples showed good linearity. The detection limit was about 0.2 ng mL^-1 . Also, the novel method for preparation of nanocomposite fiber was compared with previously reported techniques for MDN determination. The results show that the novel nanocomposite fiber has relatively high extraction efficiency.